On 4 Jul 2026, at 1:13 am, Andrew Lunn [off-list ref] wrote:

quoted

+ /* Arrival Time Stamp Mode (ArrTSMode); see the ArrTSMode encoding in
+ * hwtstamp.h. Zero (the default) leaves arrival time stamps in the
+ * switch registers; non-zero embeds them in the frame, either appended
+ * as a trailer or overwritten at that byte offset past the start of the
+ * PTP common header.

So how do you indicate trailer?

ArrTSMode being 1 (matches switch register interpretation).

Will remove (c).